Additive manufacturing is a process of creating three-dimensional parts by depositing overlapping layers of material under the guided control of a computer. Techniques of additive manufacturing include, without limitation, fused deposition modeling (FDM), fused filament fabrication (FFF), and Plastic Jet Printing (PJP). Using this technique, a material (e.g., a heated and/or pressurized thermoplastic) passes through a print head. The print head is moved in a predefined trajectory (a.k.a., a tool path) as the material discharges from the print head, such that the material is laid down in a particular pattern and shape of overlapping layers. The material, after exiting the print head, hardens into a final form.
In some applications, one or more fibers (e.g., one or more continuous or chopped fibers) move through the print head along with the material to act as reinforcement for the final solidified part. This process may be referred to as reinforced filament fusion (RFF).
Although FDM, FFF, PJP, and RFF manufacturing of structures can be an efficient way to produce high-performance and geometrically complex structures, the performance of the printed structures may be difficult to predict. In particular, mechanical properties (e.g., stiffness, strength, etc.) of such printed structures are anisotropic in nature, exhibiting different characteristics in X, Y, and Z directions.
Historically, printed structures have been created using a trial-and-error method, where the part was printed, tested, and re-printed in a different manner until a successful part was produced. This process, while ultimately successful, can also be time consuming and expensive.
Recently, finite element analysis (FEA) has been used with some success to predict the performance of a printed part. In particular, printed parts have been analyzed using FEA, for example based on characteristics of the material and bind sites located between layers of deposited material. When using FEA, a physical part may not be printed until a theoretical design is created that may pass minimum FEA thresholds.